Cannot log into T mobile account

I recently purchased the T-Mobile 5G home internet plan completely online. I created a T-Mobile ID using my phone number and email. When I tried to log in, I was asked to confirm my email and phone number. I had no problem confirming my email, but I couldn't confirm my phone number. The system kept giving me an error message:

The number (My phone number) is a MetroPCS phone number. Please visit https://www.metropcs.com to manage this line.

I’m confused as to what the issue is.